Recently, there are known television receivers which not only receive television signals to display images on a CRT (Cathode Ray Tube) display but also display image data which is written in a JPEG (Joint Photographic Experts Group) file, etc. output from a digital still camera or a personal computer.
Among such television receivers, there is known an HDTV (High Definition TV) provided with a CRT display having maximum pixels of 1920 pixels×1080 pixels (approximately 2 million pixels). Generally, since images may not be displayed on outer 10% –20% circumference of a CRT display screen, an area of 1632 pixels×918 pixels of a CRT display screen of an HDTV works as image display area which can really display images (effective display area).
So, an HDTV can display JPEG image data on a CRT display having the image display area of 1632 pixels×918 pixels.
Thus, when displaying JPEG image data of 2400 pixels×1800 pixels (approximately 4.3 million pixels), which is larger than the image display area of 1632 pixels×918 pixels, on an HDTV, part of the image data cannot be covered and the whole image data cannot be undesirably displayed.
On the other hand, when displaying JPEG image data of 680 pixels×480 pixels (approximately 0.31 million pixels), which is smaller than the image display area of 1632 pixels×918 pixels, on an HDTV, even though the whole image data can be displayed, wide range of blank area is undesirably formed since the image data is small.